Method of knurling



June g2 1926' T. D. CAMPBELL' METHOD OF KNURLIYNG- Filed Nov. 5, 1925 2 Sheets-Sheet 1 Eliwemkoz: TH CIMAE El. CAMPBELL,

June 22', 1926. 1,589,584-

T D C A M P B E LL OOOOOOOOOOOOOO NG Patented June 22, 1926 UNITED STATES PATENT OFFICE.

THOMAS D. CAMPBELL, OF CLEVELAND, OHIO, ASSIGNOR TO THE CLEVELAND FOLD- IN'G MACHINE COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

u'Ernon or xnunnmo.

Application filed November produced thereby;'the object of my invention being the production of knurled articles that shall have lands fabricated longitudiinally thereof approximately of equal height,

In the particular art to which my inven tion is applied, viz, the production of knurled. rolls for paper-handling mechanism, it is necessa to grind the lands as originally knurle while leaving a material cup or depression between adjacent lands. In the ordinary type of knurled roll the lands were unequally elevated so that it was impractical to grind more than one of the paired lands: extending longitudinally of the rolls. However, it is apparent that if .the lands maybe equally elevated, both lands of eacli 'pair separated by a cup or depression may be e ually ground, while leavingthe cup of a equate depth, if the lands are sufliciently elevated.

Accordingly, I have devised a simple and novel mode of knurling rolls or similar articles whereby the fabricated lands may be made substantially equal in height and sulficiently elevated above their intervening cups to admit of grinding both lands, whereby the use of the roll 1s very materially increased. In practicing the method of knurling these rolls hitherto, it has been thought necessary to subject the rolls to the action dressing or of the knurls advanced longitudinally thereof from end to end. Invariably the lands thus fabricated are materially unequal in height, with the disadvantage noted above.

I have discovered that by the simple expedient of twice knurling a roll or other cylindrical article, and in reverse-or opposite directions, it is possible to produce lands of substantially equal elevation upon the opposite sides of longitudinal cups or depressions extending lengthwise of the work or roll, and of sufiicient depth to permit the inding of both lands without impairin t e operative qualities or efficiency of the fabricated roll. Its wearing qualities are doubled.

It will be desirable to explain the details,

of my invention in connection with the accompanying drawings, wherein:

I Figure; .is a plan view of a lathe broken 3, 1928. Serial No. 672,690..

F Fig, 3 is a transverse section on line 3-3,

Fig. 4 is an enlarged plan view of two coacting rolls broken away near their ends,

Fig. 5 is a transverse section on line 55, Fig. 4, I

Fig. 6 is a greatly, exaggerated fragmentary view in cross section of a roll knurled after the usual manner,

Fig. 7 is a similar view of a roll knurled in accordance with my invention,

Fig. 8 is another greatly exaggerated view of the latter roll with the lands dressed or ground to a common diameter,

Fig. 9 is an enlarged, fragmentary, dimensional section, illustrating the initial knurling operation, and v I Fig. 10 is a similar fragmentary, dimensional section, illustrating the completed knurling operation, it being understood that the figures are not drawn to the scale.

Throughout the several figures of the drawings I have employed the same character of reference to indicate similar parts.

Referring first to Figs. 1, 2 and 3, the work or roll a is shown positioned in a lathe having the usual travelling support I) actuated by the under screw 0 for effecting the travel of said support longitudinally of the lathe bed 05. Two sets of opposing knurls e, e (a plurality of knurls preferably being employed in tandem to insure the desired width of knurling members) are mounted upon said support to engage the work or roll; the usual member a being provided at the extreme right'of the roll to eflect the alinement or register of the opposing sets of knurl previous to their engagement with the work a. The travel of the support and knurls is toward the left as indicated by the arrow, and the work, under high magnification, will appear approximately as shown in Fig. 6 on a fragmentary section'taken on line 6--6. Referrin to the greatly enlarged section, which shou d be understood to be typical of ordinary knurling, it will be seen that the righthand lands f are materially higher than are the thicker lefthand lands g, so that it is impracticable to dress or grind the latter and leave a material cup or depression it between such lands. Moreover, the grinding of both lands would blunt the more elevated members of the pair, if this operation were attempted, while practically destroying the cup or depression and rendering the roll unfit for service in paperhandling mechanism.

The reverse milling of the roll, after it has been completely milled longitudinally in one direction, may be accomplished either by reversing the direction of theactuating screw 0 in vthe lathe, or with better results ordinarily, by reversing the work end for end in the lathe and re-knurling the roll from right to left in the lathe, as before.

I This reverse knurling operation serves to produce lands of substantially equal height such as shown at i, i in the great y enlarged fragmentary section of Fig. 7. Moreover, the longitudinal depression or cup In is of I, sufiicient depth, so that when the acute edges of the lands are dressed or ground as shown at 2", i, Fig. 8, said cup It will insure an operative working face for the roll having substantially double the wearing qualities 1 of the rolls knurled in accordance with presorder that the knurled operative faces may handle the thinner classes of paper, such as Bible stock, in folding machines and the like.

While the re-knurling in reverse direction is very simply and readily accomplished, it

has never been attempted prior to my invention, so far as I am advised, yet the results are distinctly advantageous in producing a better knurled article, i. e., one that is knurled uniformly throughout its operative face and is capable of being ground or dressed to a uniform diameter with respect to it's lands, while preserving the intervening cup or de ression. It is apparent that with duplicate ground lands a paper-handling roll will have twice the effective life as compared with the knurled rolls of the prior art.

As a specific example of knurl ng high carbon rolls for paper-handling machines, such as folding machines and the like, I may instance the initial knurling of the roll from right to left with an increase in' its operative diameter of from .006" to .007 This operation is diagrammatically indicated in Fig. 9 of the drawings wherein the radial increase of one-half the above figures is shown with respect to the land 7 upon the right. The reverse operation of knurling preferably is accomplished by closing the knurls .slightly upon the work; actuating the screw 6 (Fig. 3) for this purpose. Thereupon it will be found that the lefthand land will be raised substantially to the same height as the one on the right, while the latter will be further elevated approximately .001" to .0015; these dimensions being indicated in the diagram of Fig. 10, of which the fragmentary section of Fig. 7 is typical. These dimensions, of course, are given merely by way of illustration in adaptlng my invention to the specific purpose indicated. The displacement and shaping of the metal quite obviously are largely under the control of the artisan and the reverse operation of knurling, preferably with closer adjustment of the knurls, alone is required for the fabrication of rolls capable of much longer continued use than was hitherto possible.

Having now described the preferred method for practicing my invention andv for producing the new and novel article of manufacture above described, I claim as new, and desire to secure by Letters Patent, together with such modifications as may be made by those ordinarily skilled in the art, the following: -1. The herein described method of fabricating knurled rolls, which consists in subjecting the roll progressively to the action of theknurl throughout its length and completing the knurling action in a reverse direction, substantially as set forth.

2. The herein described method of fabrieating knurled rolls for handling paper and the like, which consists in subjecting the roll to the action of opposing knurls advanced longitudinally in one direction and completing the knurling action by effecting the relative advance of the knurls along the roll in the opposite direction, substantially as set forth.

3. The herein described method of fabrieating knurled rolls, which consists in subjecting the roll progressively to the action of the knurl throughout its length, completing the knurling action in a reverse direction whereby lands are produced of substantially equal height, and grinding said lands to produce a working surface of uniform diameter, substantially as set forth.

4, The herein-described method of fabricating knurled articles, which consists in subjecting the blank to the action of oppos ing knurls and re-subjecting the blank to the action of knurls more closely approximated to each other, substantially as set forth.

In testimony whereof I do now affix my signature.

THOMAS D. CAMPBELL. 

